If it takes one person 4 hours to paint a room and another person 12 hours to
paint the same room, working together they could paint the room even quicker, it
turns out they would paint the room in 3 hours together. This can be reasoned by
the following logic, if the first person paints the room in 4 hours, she paints 14 of
the room each hour. If the second person takes 12 hours to paint the room, he
paints 1 of the room each hour. So together, each hour they paint 1 + 1 of the 12 4 12
room. Using a common denominator of 12 gives: 3 + 1 = 4 = 1. This means 12 12 12 3
each hour, working together they complete 13 of the room. If 13 is completed each hour, it follows that it will take 3 hours to complete the entire room.
This pattern is used to solve teamwork problems. If the first person does a job in A, a second person does a job in B, and together they can do a job in T (total). We can use the team work equation.
Teamwork Equation: A1 + B1 = T1
Often these problems will involve fractions. Rather than thinking of the first frac-
tion as A1 , it may be better to think of it as the reciprocal of A’s time.
World View Note: When the Egyptians, who were the first to work with frac- tions, wrote fractions, they were all unit fractions (numerator of one). They only used these type of fractions for about 2000 years! Some believe that this cumber- some style of using fractions was used for so long out of tradition, others believe the Egyptians had a way of thinking about and working with fractions that has been completely lost in history.
Answer:
b = 55 degrees
Step-by-step explanation:
The angles 30, a, b and 45 must sum up to 180 degrees
Subtracting (30 + 45) from both sides leaves us with a + b = 105 degrees.
But b = a + 5. Substituting a + 5 in the equation above yields
a + a + 5 = 105 degrees, so that
2a = 100 degrees, and a = 50 degrees. Then b = a + 5, or b = 55 degrees.
Answer:
8
Step-by-step explanation:
12c=22
6c=11
c=1 5/6
20c=33
c= 1 13/20
5/6 is about .83
13/20 is .65
12 chocolate bars for $22 is about $1.83 each
20 chocolate bars for $33 is $1.65 each
The 20 chocolate bars for $33 dollars has a better unit rate and is a better buy.
